Format the textbox to replace the set placeholder values with the entered values real time

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Globalization;
using System.Text.RegularExpressions;
using Microsoft.VisualBasic;

namespace frmMain
{

    public partial class frmMain : Form
    {
        
        public frmMain()
        {
            InitializeComponent();
        }


        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            //Remove previous formatting, or the decimal check will fail including leading zeros
            string value = textBox1.Text.Replace(",", "")
                .Replace("$", "").Replace(".", "").TrimStart('0');
            decimal ul;
            //Check we are indeed handling a number
            if (decimal.TryParse(value, out ul))
            {
                ul /= 100;
                //Unsub the event so we don't enter a loop
                textBox1.TextChanged -= textBox1_TextChanged;
                //Format the text as currency
                textBox1.Text = string.Format(CultureInfo.CreateSpecificCulture("en-US"), "{0:C2}", ul);
                textBox1.TextChanged += textBox1_TextChanged;
                textBox1.Select(textBox1.Text.Length, 0);
            }


        }

        private bool TextisValid(string text)
        {
            Regex money = new Regex(@"^\$(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?$");
            return money.IsMatch(text);
        }

        private void frmMain_Load(object sender, EventArgs e)
        {
            textBox1.Text = "$0.00";
            //textBox1.SelectionStart = inputBox.Text.Length;
        }

    }
}